I've seen the boxer dog cakes where they are laying down I would like to try this. How do you make the body? Is it all cake?

Welcome to CC me30. The body of the cake is usually carved cake and the head is Rice Krispie treats (RKT) - but someone else will come along and explain more.

I've made some...if the head is down you can do it all cake...

I did a scooby cake (you can see it in my pictures) and used the wondermold for the head and rump with a round cake inbetween as the neck/snout. You do like 4 cups of batter for the head and the 6 cups of batter for the rump area.